Assigwobs to the super-glass compahy



C. AND V. SHUMAN. REINFOIICED GLASS AND METHOD 0F MAKING THE SAME.

APPLICATION FILED APR-20| I9I6- 1,324,361. Patented De@ 9,1919.

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ttomog sheet composed of two sheets ofglass with an sans Partnr onirica. f

CONSTANTINE SHUMAN' AND VICTOR SHUMAN, OF PHLADELPHIA, PENNSYLVNIA, ASSIGNORS TO THE SUPER-GLASS COMPANY, A CORPORATION GF 3EENNSYLVANIA.l

REIN FORCED GLASS AND METHOD 0F. MAKING THE SAME.

Specication of Letters Patent.

Application led April 20, 1316. Serial No. 32,355.

To all lwhom t may concern:

Be it known that We, CONSTANTINE SHU- MAN .and VICTOR SHUMAN, citizens of the United States, and residents of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented an llmprovelnent in Reinforced Glass and Methods of Making the Same, of which the following is a specification.

The object of our invention is to provide an improved method for making a compound transparent or translucentcomposite an interposed sheet or. body of Celluloid welded to the glass sheets and uniting them to the Celluloid to form a unitary structure.

Heretofore, the making of a transparent composite sheet, by pasting a sheet of celluloid or 'equivalent material between two sheets of glass by some kind of cement, or by softening and dissolving the surface portions of the Celluloid sheet with a solvent of Celluloid and withL suchl preparedcelluloid sheet gether while under pressure, has been known; these processes havehowever, seri ous objections and the products produced by their use have not been found satisfactory. In case a cement is used, it has been found that the proper results Cannot be obtained without adding a material which has tendency to discolor intime; ,and in Case a solvent is used to dissolve the outer surfaces of the Celluloid to form a Celluloid cement, it has been found impossible to remove all of the solvent` that -remaining imparting a weakening of the product.

In order to secure a desirable transparent compound sheet.y which shall possess the 'property of not allowing glass splinters, or pieces to fall 0H when struck and cracked by a hard blow, we have found it necessary that the compound sheet shall be composed solely of glass andg celluloid, the latter in its normal state and not `weakened by the addition of any solvent.

Our improved process of making oomposite, transparent or translucent sheets, consists of assembling two sheets of glass, (with or without dry Celluloid coatings), one on each side of a sheet of .Celluloid and subjecting the assembled sheets to pressure, and at or `before the application of the welding pressure, raising the temperature prefasting the two glass sheets to.

erably to approximately 230 Fahr., next applying a higher pressure, and after maintaining the assembled productv under this heat and pressure for a predetermined time,

)Patented Dec. 9, 31919.

finally lowering, the temperature and releasing the .pressure before removing the sheet. @ur improved method may be further characterized by employin a vacuum about the associated sheets of g ass and celluloid during the application of pressure; and in the most approved adaptation'of this feature of our invention, we` prefer that the y vacuum shall not only be maintained in the space occupied by the sheets, but also within the space containing the pressure applying Huid, whereby the vacuum is essentially for extracting the air from between the glass and celluloid and not for the purpose of applying the o erative pressure to insure the welding of t e sheets together.

Our invention contemplates the use of a sheet containing compartment, from which, preferably, the air may be exhausted," and an inclosing pressure chamber in which,

a pressure may be Created, the wall or walls between the compartment and the inclosing chamber being flexible whereby the pressure of the. inclosing chamber may be applied to the sheets of glass and Celluloid to press them together to form the welded union, as aforesaid.

@ur invention also comprehends certain other features of invention, which, together with those above specified, `will be better understood by the more detailed description hereinafter contained and by the definitions thereof recited in the claims.

Our improved apparatus in which to carry out our special process or method is fully illustrated in the drawings, in

which :-l5`igure 1 is an elevation of our im.

proved apparatus with the compartment and Chamber in section; Fig. 2 is a plan view clamped to the tank by bolts 3a. rlhe width land length ofV this tank are required to be large enough to take in the frame 36 iii which the glass to be treated is placed, butv the height of the tank may be relatively small. Therefore the dimensions of the -of the same with part in section; and Fig. 3 is an enlarged sectional view of a portion of does not become air-bound.

lbottom and a circulating pipe 13 opens from the tank ata materially ,higher level andcommunicates with a coil 14 in a tank 15,

the other end of the coil being connected with the pipe 5 at a point between the pump 6 and the tank. At a suitable place between the coil 14 and the tank and in thel pipe 5 is arranged a circulating pump 8 of any suitable character, the purpose of which is to draw the fluid through the coill 14 and yforce it into the tank and permit it, after circulation therethrough, to pass by the pipe 13 into .the other end of the coil. rlhe pipe 13 is provided with a pressure gage 24 and witha temperature gage 25, so that the pressure within the tank and the temperature. of the circulating fluid therein may be readily known at any time during the process. r1`he pipe 5 between the circulating pump 8 and the pressure pump 6 is provided with a shut-olf valve 7 which is preferably closed when the circulating pump is in operation. While this valve`7 is not essential in view of the check valves employed in the force pump 6,'nevertheless itl is desirable to provide a positive valve 7 which may be closed during the circulation of the fluid when under high pressure, that the said pressure may be positively maintained. llhe tank 15 is provided at the top wit/h a steam pipe 16 having a valve 17 and a water overflow pipe 22 having a-valve 23. The bottom of this tank is provided with a drain pipe 18 having a valve 19, and 'a water inlet pipe 20 having a valve 21. lif the valves 21 and 23 are closed and valves 1-7 and 19 are opened,

steam may pass into the tank around the coils 14 to heat thefluid, and the water of condensation will flow off' by the pipe 18. lf high -pressure steam is employed, the valve 19 may be opened only just sullicient to let the water of condensation drain off under the initial pressure of the steam without permitting an excessive Vescape of steam. Furthermore, the air liberated by the condensation ofthe steam is passed over with the water of condensation so that the tank ln this manner, the circulating fluid through the tank 2 may be heated to the desired degree.A lf, on the other hand, Valves 17 and 19 are closed and the valves 21 and 23 are opened,

thenthe cold water will enter at the bottom of the tank and fill it and flow out of the pipe 22. ln this manner, the circulating fluid through the coils 14 will be cooled. By the apparatus just described, it will be evident that the temperature of the circulating fluid in the tank 2 may be either heated or cooled to any desired degree, and the time under which these actions are maintained may be predetermined to suit the requirements of the process. During these operations, the tem erature conditions may be readily read by t e gage 25.

1n filling the tank, it is manifest that the same might be filled through the pump 6 and pipe 5, but as this would be slow and not as satisfactory as filling the tank by the normal hydrant pressure ofv the street mains, We prefer to connect with the pipe 13 a water feed pipe 26 having a valve27. Furthermore, the cover 3 ofthe tank is provided with an overflow pipe 11 having a 'shut-olf valve 12. 'llhis overow pipe 11 is preferably located at the highest interior part of the tank chamber, so that air may readily flow out of the tank in the act of filling it, but this is not essential if a vacuum pump is employed as provided for hereinafter.. ln filling the tank after the cover has been clamped tightly in position, the valves 27 and 12 are opened and the 'water or fluid passes through pipe 26 and pipe 13 into the tank, while the air flows out of the g pipe 11 from the upper part of the tank. @When the water completely fills the tank and begins to flow vout of the pipe 11, it will be known that the tank is completely full and then the valves 27 and 12 are closed. ln the filling ofthe tank in this manner, there would be no appreciable pressure within the tank, and it will therefore be understood that whatever pressure is required will be provided by the operation of the porting the layers of glass and Celluloid in.

proper relation to insure their being welded together, while bein subjected to the action of temperature an pressure provided by the uid contents of'th tank. A frame 36 to provide a hollow chamber. 44 is arranged to be supported upon the lateral projections or lugs 4 from the side walls of the tank at a distance above the bottom thereof. rllhis frame 36 comprises alower rectangular heavy frame 37 and asimilar upper rectangular heavy frame 38, between which is clamped a corresponding frame 39 which acts as a spacing frame to insure the proper vertical width of space 44 in which to locate the glass and celluloid. 0n each side of the frame 39 is a rectangular packing or gasket 41, and arranged between these gaskets and iso the respective frames 37 and 38 are exible sheets 42 and 43 of galvanized iron or other suitable metal, or iffdesired, the lower sheet 42 might be of galvanized iron and the upper sheet 43 of copper to give somewhat more flexibility. The several frames 37, 38 and 39 are bolted together bythe numerous bolts .-40, and in that manner clamp the frame parts together tomake a fluid-tight chamber 44 betweenothe metal plates 42 and 43. 45 and'46 represent the two sheets of glass, and 47 is a sheet of celluloid arranged between the glass sheets, and these three i sheets are placed within the chamber 44 resting upon the lower metal sheet 42 and having the upper sheet 43 close to the surface of the upper sheet of glass. It will be understood that when the pressure is applied to the fluid in the tank surrounding this frame 36, the flexible sheets 42 and 43 will be forced toward each other and press uniformly over the lower operating surfaces of therespective glass sheets and force themtightly upon each side of the celluloid, compressing the latter between them and into tight intimate contact. If air was within the chamber 44, said air would be compressed during the pressing of the sheets together, and the air between the glass and the celluloid would be forced out during the welding operation. We, however,`prefer to provide exhausting means by which the air may be exhausted from the chamber 44 after the glass and celluloid have been sealed therein. To permit the exhaustion of the air, the intermediate annular frame 39 is provided with a vent 48 terminating in a tube 49. If it is desired y to exhaust the air from the chamber 44 before it is put into the tank, that may readily be done by withdrawing the air through the pipe 49 and sealing it. We prefer, however,

to exhaustthe air from the chamber 44 after the frame 36 has been placed in the tank 2 Aand during the operation of the process.

The means employed for this purpose and for exhausting the air from the tank 2 itself is as follows -A vacuum pump 32 is connected by pipes 28 and 31 with the tank 2, and said pipes 28 and 31 extend upward abovel the top of the tank and preferably conneet through a reservoir chamber 30. A valve 29 may be provided in the pipe 28 adjacent to the tank to close the communication with the vacuum devices after theexhaustion has been complete and before the pressure is applied by the pump 6. Branching from the pipe 31 is a pipe 33 having a valve 34, said pipe opening into a passage through` the tank wall, .the inner end of which is provided with a nipple 35 in alinement with the pipe 49, and these two are bonnected by a heavy rubber union 50 duringy able extent of vacuum'may be provided and malntained, if desired, withinthe said chamber 44 during the operation of the process.

The provision of a preliminary vacuum inthe tank 2 while exhausting the air from the chamber 44, prevents atmospheric pressure (acting through the sheetsl 42 and 43) from forcing the two glass sheets upon the celluloid during the exhausting of the air from between` them, and consequently guard against interference with free withdrawal of the air which might otherwise be entrained. After this action is'accomplished, the valve 29, and if desired, the valve 34, will be closed, and then the pressure would be applied in the tank 2 by the pressure pump 6 to introduce the positive pressure for insuring per` Afeet welding betweenthe glass and celluloid. Preliminary to this last operation, namely, the application of the welding pressure, the vacuum in the tank 2 may be broken, and this may bedone by simply opening the valve 12 for a moment, and then closing it or by pumping in the water.

l/Vhile ordinarily, water may be used as the pressure fluid in the tank 2, it is to be understood that we do not restrict ourselves to a liquid, as air or any suitable gas may be employed as the Huid for controlling the pressure and supplying the temperature to the chamber 44 in-which the glass and celluloid are located, and therefore in using the less we do not restrict ourselves in this respect, for as before pointed out, the genera lV process may beoperated without the use of a vacuum. The special advantage of employing a vacuum in the tank outside of the chamber 44 at the same time that a vacuum "is being applied within the chamber 44, re-

sides lin the fact that by removing the atmospheric pressure which would be applied to the sheets- 42 and 43 (under'the conditions of a vacuum in the chamber 44 alone), there is no compression p'ut upon the sheets of glass and celluloid during` this exhausting operation, and consequently the atmosphere of the chamber 44 can' be rarefied to the highest degree possible, and then while there is no air present in chamber 44 the pressure may be applied inthe tank2 by means of the fluid and plump' 6 vto insure the compression 'of the glass sheets upon the Celluloid to provide a perfect welding of the surfaces withoutl any possible entraining of air, even in-l within the tank and put upon the surface of the glass from the outside 'of the frame.

Y 36, thereby insuring a very .thorough weld? ing and with the Celluloid in a perfectly solid and dry condition, so that when the composite glass sheet is subsequently released from its confinement within the frame 36, there is no possiblity of the'atmospherc pressure entering .between the glass and Celluloid to interfere in any manner with the perfect welded union which has been' made.-

Briefly stated, the process or operation for welding together the two sheets of glass 45 and 46 to an intermediate sheet of celluloid 47, is as :Eollowsz-'The' sheets or glass, preferably with their Contacting surfaces perfectly clean, are placed uponopp'osite sides of a Cleai sheet of Celluloid 47 and these sheets are thenv placed within the 4frame 36 after the top plate 43 and frame -38 have been removed. `These parts are then placed .in position and the bolts 40 inserted and tightened .so as to make the chamber 44 airtight except so far as communication-may be had through the nozzle or tube 49. rThis frame 36 thus charged with the glass and Celluloid is then placed .in the tank and rests uponthe lugs 4 and preferably with the greatest clearance between the endj of the' 'frame and the side of the tank at the end most distant to where the water is circulated.

throu l1 pipe 5. When the frame 36 is place in position in the tank, the pipe 49 is'coupled to the nipple 35 by the rubber.

lThe valve 410 being closed and the cover 3 being tightly clamped in place, waterA is adthrough the vent 11, `the valve 12 of which has been opened. The water fills the tank as well as the pipes 13, 5 and coil 14, and

will also ll the Circulating pump 8, andif the valve 7 isopened, the'water may extend Y .all the way back to the pressure pump 6.

When the water begins to dow from the overlowpipe 11, the valve 12 is Closed, the

,Leanser valve 27 is also closed, andthe vacum pump 32 put into operation with the valves 29 and 34 opened. When the desired degree of vacuum has been put upon the chamber44 `and also uponthe water in the tank 2, the valve 29 is closed' and the valve 3 4 may also be Closed or, if desired, valve 34 may be left v open and the lvacuum pump continue to act in maintaining the vacuum within the cham- .ber k44. Any suitableI well Iknown means may be employed to indicate the* extent of vacuum. After the removal of the air, addiculation enters the tank by vpipe 5 passing L under the frame 36 to the distant side, thence upward around the end of the fra-me and back over the frame and thence out by the .pipe 13. To insure this circulation to the extremev end of the. frame 36, aloose illing plate 36,a may be allowed Ato rest upon the top of the frame 36 closing the space between the tank and frame at its sidesand end nearest to the pipes 5 and 13, as indicated at 36a in Fig. 1, and in dotted lines inFig. 2. 'llhe duid from the pipe- 13 passes through the coil14 and back to the'pump 8. During this circulation, steam is turned on to the tank 15 byJvalve 17, and in passing over the lcoil 14 gives up its latent heat to. the vcirclatinggf water within the coil and the condensed water passes to the bottomand out by pipe 18 and valve 19. The temperature of the circulating fuid is gradually raised until the fluid is heated to about 230 Fahr. temperature ofthe-Huid is conducted to' the glass andl Celluloid and softens the latter,

- while held under Athe gentle pressure of ten poundsper squareinch. The temperaturel "of the.v circulating .fluid may be observed by perature has reache about 230 Fahr., and

while the fluid is stillbein circulated by the rotary pump 8, a small ad itional amount of fluidis pumped into the system by the pump 6, the valve 7 being temporarily opened for the admission of this additional fluid. This addition `of the circulating fluid is made very gradually and until the pressure-gage 24 indi- -`Cates a pressure of about one hundred pounds (by way of example). This increased pressure istherefore applied to the Celluloid between the two glass sheets and at a time that the Celluloid is softened by the temperature y 4of the Circulating Huid. After a reasonable .length of time to insure Yfull setting of the glass and Celluloid into thorough and intimate Contact (which may be from Iive `to thirty minutes, 'according to the thickness ofv the glass), the steam is shut oli' by valve 17 This Y and valve. 19 is also Closed. Cold water is then admitted by valve 21 and allowed to overflow by opening the valve 23. Thiscold water flows over the coils 14: and Cools the circulating fluid, the latter still being circulated by the rotary pump 8. In this manner, the circulating fluid is Cooled until the thermometer indicates about 100O Fahr.,

which is sufficiently low for handling and removing the glass.

After the Circulating fluid land the glass within the frame 36 have thus been Cooled, the pressure is gradually released by opening the overflow valve 12 until atmospheric pressure is Within the tank 2. The drain valve 10 is then opened and the fluid contents run off from the tank 2by the drain pipe 9, or at least sufficiently low tofexpose the frame 36 containing the glass and celluloid. The Cover `3 of the tank 2 is then removed. The vacuum valve 34 is then Closed. The frame 36 is then lifted out, having been disconnected from the rubber tube 50'. The vacuum is thus broken within the Chamber plicationmay be before or during the apf 44.' The frame 36 may then be opened by removing the nuts from the bolts 40 and lifting o the upper frame 38 and its flexible metal sheet 4:3. The composite glass and Celluloidsheet is then removed.

While we have designated Certain temperatures and pressures by wayof example,

' we do not restrict ourselves to the same as any temperatures and pressures suitable may 'be employed, but those stated3 have been found satisfactory in commercial practice. In some cases, the welding pressure may be raised very high even to one thousand pounds or more. per square inch where very thick plates of glass are to be weldedto thefcelluvaried. For instance, if-the composite sheet is tobe of medium area and be formedof thick glass, the entire pressure may/be promptly. applied veven before the 4heating ofthe glass yand Celluloid takes place', or the heating andthe pressure may be applied at l the lsame time. It will.- be understood. of. course that'` to insure a proper weld between the Celluloid and the glass, it isessential that the Celluloid shall b e heated? so as fto be softened and conform 'to the general vsurface of the glass at the time that the pressure is being applied, but its immediatetime of ap-` vplication of such welding pressure. ln' the case of thin sheets where the glass might readily crack, it is preferable to first apply the temperature to soften the Celluloid be fore applyingthe welding pressure. It is also to be understood that while it is prefer-y' able (where thin 'sheets of glass are employed) that therejshall be a-preliminary low pressure applied to the glass and cellulo1d sheets before the Celluloid is` softened, and before the application of a full press sure, this preliminary low pressure may be omitted where desired, and especially where the glass, sheets are -relatively thick.

It will be observed that in forming a composite sheet of Celluloid with outer glass faces in the 'manner herein described, the

two glass sheets are held together by the Celluloid sheet which is welded to each of the glass sheets and acts as a binder between them, and this welding. operation is by thorough intimate contact between the glass and Celluloid with the complete exclusionof air, and consequently a'most practical and strong structure is secured. It will further be noted that when the welding -is done in this perfect manner, the transparency of the composite glass and Celluloid sheet is most.

excellent; and as Celluloid alone is used between the two glass sheets, the tendency to discoloration is eliminated While it 'is most desirable that the two sheets of glass and an interposedsheet of Celluloid are alone employed, it will be Amanifest that thecsame process-may be l carried out where the glass surfaces tobe welded are first painted or-coated by painting or spraying with a very thin' layer -of Celluloid dissolved ina solvent which, for example, may be a mixture of 95% alcohol and-5% crystallized camphor, and whenr dry placed upon opposite sides of a sheet of Celluloid withv their painted or coated sur- Y faces in Contact therewith. A coating of this kindstick's very tightly to the glass;

and after all of the solvent has'beenevaporated (which may be' assisted byhigh temperature or otherwise.) the remaining deposit is pure Celluloid as a thin skin onV the.

glass and very tightly adherent thereto. As Celluloid will 'weld .somewhat better to eelluloid thalritwill to glass, this pre-treatment of theglass'to obtain avery thin skin of pure adhering Celluloid is an advantage to the .process and the product.

Thisl reference tothe coating of the glass with celluloidin a solvent isnot to be confused with. the idea of sticking the glass sheets together by said coatings as a cement and subsequently: evapora-ting the solvent, as the solvent in thisV case is a mere incident to coating the surface of. the glass with a very thin layer of pure tightly adhering Celluloid which is in adry hard Condition upon eachsheet of the glass before they arel assembled in connection with the Celluloid sheet within the apparatus and to receive treatment by the special process-herein set out. rlhe result is a true welding together of asurface of adherently coated dry celluloid to another surface of celluloid under j bodied the features of advantage enumerated herein asdesirable, and while we have in the present instance Ashown land described by way of eXample the preferred embodiments thereof which have been found in practice to give satisfactory and reliable results, lit is to be understood that we do not restrict ourselves to the details, as the same are susceptible of modification in various particulars without departing from the spirit or scope of the inventionv In this application no claim is made specifically to the apparatus norto /the method of.. making an article of the nature herein described and in which lthe sheets of glass are first coated with a suitable layer of adhering substance before being united upon the sheet of celluloid, as the same have been divided out of this application and form subject matter of Letters Patent No. 1,274,206, dated July 30, 1918, and No. 1,274,205, dated July 30, 1918.

Having now described our invention, what we'declareis new and desire to 'secure by Letters Patent, is I 1. The herein.a described process ofmaking composite sheets of a morey or less translucent character, which consists of assembling two sheets of glassfand a sheet of celluloid between them,holding the glass sheets ,upon the celluloid sheet with a relatively low initial pressure, then raisin the temperature' of the assembled -glass and celluloid sheets to softenthe celluloid, and while the cellu f loid is inv softened condition applying a rela? tively highp-r'essure. upon the glass-'sheets suiicient to force an intimate .contact with @bling two sheets w the celluloid throughout itsr entire surface to lweld the two sheets of glass vto the cell'uloid, and finally loweringthe temperature andv removing the pressure of th'e composite sheetthus formed.

2. The herein described process of making composite sheets of-a more or less translucentv charactenwhich consists of assembling two sheets of lass and as heet of celluloid between them, olding the glass sheets upon the celluloid lsheet with a relatively low initial pressure, then raisingthe temperature of the assembled glass and celluloid sheets to approximate] 230 Fahr. to soften the celluloid, an while the celluloid `is' in so ,tened conditionap'plying-a relatively high pressure upon the glasssheets suhcient to force an intimate Contact with the^cellu1oid throughout its entire surface to weld the two sheetscfglass to the celluloid, and tinally moving the pressure of the composite ,sheet thus formed. I

3. rlhe herein described process of making composite sheetsy of a more or less translucent character, which consists of assembling two sheets of glass and a sheet of celluloid between them, removing the atmospheric pressure from the assembled sheets, then subjecting the said assembled sheets to an initial pressure upon the outer surfaces of the glass to maintain the glass `sheets yin rm contact with the celluloid, then raising the temperature of the assembled sheets suiiciently high to soften the cellnloidfthen applying a relatively high pressure upon the oute/i` surfaces of the glass sheets to press the said sheets tightly upon the softened celluloid to insure a thorough welding between the adjacent surfaces of the glass' andthe celluloid, and finally lowering the temperature and pressure of the composite sheet.

4. rlhe herein described process of making l ocomposite sheets of a more or less translu- `cent character, which consists of assembling two sheets of glass anda sheet of celluloid lbetween them, removing the atmospheric pressure from about the assembled sheets, then subjecting the celluloid to a tempera-4 ture. suiciently high to soften it, then applying a pressure to the outer surfaces of the sheets of` glass sufficient to press the adjacent surfaces tightly upon the softened celluloid to insure continuoussurface con- '.tacting therewith to produce a thorough vwelding, and finally lowering the temperature and pressure, the temperature being lowered to a condition which will permit the composite sheet to be handled after which cooling of the sheet the pressure is finally' removed.

5. The herein described process of making composite sheets of va more or less translucent character, which confsists of assemof glassand a sheet of cellu loid between them, inclosing the assembled -sheets of glass and compartment,

pressure from within said compartment", subjecting the celluloid to a temperature sufficiently high to soften it and applying a' pressure'to., force the two sheets of glass tightly upon the softened'celluloid to weld -the surfaces together during the time that they are inclosed withinfthe chamber-and out of .Contact with atmospheric pressure. lowering the temperature and pressure and permitting the entrance of atmospheric pressure to the compartment containing-the composite sheet, and iinally.,removing the same from said compartment. 6. The herein described process of making compositev sheets of a more or less translucentcharaCter, which consists of assembling. two flat sheets of glass and a flat sheet of celluloid within a closed' Y removing the atmospheric Celluloid between them, inclo'singthe assent-fj bledsheetsof glass and celluloidwithin a closed compartment, removing the atmospheric pressure from Within saidcompart. .'ment 'and therebyfbringingthe Walls of the compartment in contact withy the glass sheets, subjecting the Celluloid to a temperature' sufficiently; high to soften it by of fifty pounds tothe walls'of the compartheat conducted-through the walls of the compartmentLand applying a pressure in excess ment to forcefthe two Sheets ofglass tightly upon the softened Celluloid to weld the'sur faces together during the time-that they -are inclosed -within'the chamber and out of cion'- tact with atmospheric pressure, then 'lower-j ing the temperature while maintaining pres'-, Asure to harden'- the Celluloid, theny removing- 1 the pressure applied tothe outer surfaces of the glass, then'v admitting, atmospheric pressure to the compartment c ontaining rthe composite sheet, and finally removing the composite sheet. i '1 7. The herein describedprocess of makiing composite sheets of a more or lessi translucent character, which consists of as'- sembling two sheets of glass and a sheet of zelluloid between them, inclosing the :asv ',sembled sheets Awithin a -closedj compartment, surrounding the closed compartment with va fluid, heating the fluid to raise the temperature of the compartment Auntil the celluloidbecomes softened, then increasing the pressure of the fluid and causing it to"v apply pressure throughthe :walls of Vthe compartment uponthe outer sur-faces of the two .sheets of glass out of contact withthe compressing fluidl to press lthemv tightly upon the softened Celluloid whereby they are thoroughly` welded vthereto throughout their entire contacting surfaces, then lowering the temperature of the fluid and removsembled sheets within a sealed compartment inclosing ithe'fsaid compartment and lits contents within an outer compartment, introducing a fluid within the outer comying the pressure' therefrom, and-finally removing the composite sheetfrom the comparlamenti a 8. The herein .described process of making composite sheets of a more orless translucent character,'which-'consists of assembling two sheets of glass and a sheet of Celluloid between them, inclosing the aspartment and outside oflthe'vinner compart-A ment, circulating thel fluid over the innerl l compartment and through a' closed circuity outside of the outer compartment, heating the 1Huid while circulating outsidel of.A the compartment whereby heat is transferred to the inner compartment'sufliciently to soften the celluloid contained therein, then l increasing the'pressureof the fluid and'causing it to act upon theouter surfaces' of the glass sheets. without contact therewith by flexing the walls', vof the inner compartment, and v thereby pressing the glass sheets 'tightly upon the softened Celluloid to thoroughly weld thecontacting surfaces, then cooling` the circulatingl fluid. to cool the ffcelluloid.

and ,glass tofharden the Celluloid', then lowlering the pressurefof the fluid, 'andflnally removing the 4composite 'sheet' from. the iiiner compartment and out ofthe influence of the fluid. n;

9. T.he herein` describedprocess of mak' ing composite sheets of a more or less translucent character, which consists 0f assembling two sheets of glassand a sheet of Celluloid between them, -inclosing the as'-` lsembled sheets within-a closed compartment,

surroundingjthe closed compartment with aV fluid, exhausting air from ,out of thev closed compartment and from between the sheets therein, heating the fluid "to raise the' 'e5 temperature ofthe compartment until the Celluloid becomes softened, then increasing l.the pressureof'the flui'd'and causing it to apply pressure through' the walls of the compartmentupon the outer surfaces of the 'two sheets of glass to press them tightly upon" the softened Celluloid lwherebyvthe-y are thoroughly. welded thereto throughout their .entire contacting surfaces, then lower- .ing the temperature of the fluid and removing `the pressure therefrom, and finally admitting atmospheric .pressure to the compartment andv removing` the composite sheet from Vthe compartment.

l0, The herein described process of making composite sheets of a more or less. translucent character, vwhich consists of assemblingtwo sheets of glass `and a sheet of cellu' loid between them, inclos'ing the assembled sheets within a closed compartment, surrounding-the said compartment with afl-uid inclosed in an outer closed compartment, removin the atmospheric pressure from withint e inclosed compartment and from between the sheetstherein vand also from the outercompartment containing the fluid, raising the temperatureof the fluid to soften inclosed compartment to 'force' the glass sheets tightly upon the softened Celluloid to insure their thoroughwelding together, then lowering the temperature of 'the fluid to cool the Celluloid and-removing the vpressure from the-fluid, and finally admitting atmospheric pressure to 'the' inclosed compartment and removing'the composite sheet.

11.v As a new article of manufacture, a. composite .sheet through which light raysv the' Celluloid, then'applying a high-pressure 'to the fluid and by Ait to the walls of the spending to the Varying distances between the glass sheets and the yarying thickness of said Celluloid, whereby all 'air 1s excluded from between the celluloid and glass and a perfect welding off the surfaces is provided,

' V12. As a new article of manufacture, a composite sheet through' which` light may.

pass to a greater or less extent, consisting oiftwo sheets of glass and one sheet of cellu- 'lloi'd between themsaid glass and Celluloid tightly welded together and for-ming' a unitary lstructure as a whole.

13. The herein described method Vof pro- I: vduein'g composite sheets through whichv .light rays may pass to al greater or less eX- tent, which consists in assemblin a sheet of celluloid between two sheets oi glass and fwelding the said sheets of glass to the celluloid between two sheets of lass and welding 25 the said sheets of glass tot e Celluloid sheet by theapplication of heat and pressure, and lowering the temperature to insure the hardening of the celluloid before removing. all of the pressure. f

` 15. The'herein described method of proof celluloid between two sheets of glass, removing the air from between the sheets by the ald of a vacuum, and then applying heat and pressure to the two outer side surfaces of the glass sheets while the edges ofall of the sheets. are under' the influence of a vacuum.A

lntestinony of whichnvention, we hereunto set our hands.

CUNSTANHNE SHUMAN. VCTOR SHUMLAN. Witnesses:

Been WORRALL, ADELAIDE WATSON.

-ducing composite sheets through which light rays may passte a greater or less extent,

which consists in assembling together a sheet 

